Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 8, NWS San Diego, CA

July 31, 2012Riverside County, California

NWS San Diego, CA issued this flash flood warning at Jul 31, 2012, 11:51 AM PDT for Riverside County, California. It was in force for 105 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 31, 2012, 11:51 AM PDT (18:51 UTC)
Expired
Jul 31, 2012, 1:36 PM PDT
In force
105 min
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

County Riverside County, CA

The radar

The San Diego radar (KNKX), 129 km from the middle of the area, began a volume at 18:51 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Jul 31, 12:12 PM PDTFLASH FLOOD5 Ne Indio, CADILLON ROAD AND FARGO CANYON ROAD FLOODED.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

San Diego, CA (KNKX), launched 12:00Z, 6.9 hours before the alert went out and 149 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, San Diego, CA at 12:00Z on 2012-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, San Diego, CA at 12:00Z on 2012-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1285 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

108 
WGUS56 KSGX 311851
FFWSGX
CAC065-312045-
/O.NEW.KSGX.FF.W.0008.120731T1851Z-120731T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
1151 AM PDT TUE JUL 31 2012

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL RIVERSIDE COUNTY IN SOUTHERN CALIFORNIA...

* UNTIL 145 PM PDT

* AT 1140 AM PDT...HEAVY RAIN FROM A SLOW MOVING THUNDERSTORM WAS  
OVER THE LITTLE SAN BERNARDINO MOUNTAINS EAST OF THE TOWN OF 
COACHELLA. 

* FLASH FLOODING AND MUD FLOWS ARE POSSIBLE ON DILLON ROAD AND THE 
EASTERN SECTIONS OF THE COACHELLA VALLEY. FLASH FLOODING IS ALSO 
POSSIBLE ON INTERSTATE 10 EAST OF INDIO. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DEBRIS FLOWS...INCLUDING MUD AND ROCK SLIDES...ARE EXPECTED WITH THIS
STORM. MUD SLIDES AND ROCK SLIDES CAN POTENTIALLY TRAP AND KILL
PEOPLE CAUGHT IN THEIR PATH.

&&

LAT...LON 3385 11613 3383 11613 3374 11600 3374 11594
      3352 11595 3352 11609 3391 11626 3391 11618

$$

MOEDE
3 follow-up statements
436 
WGUS76 KSGX 311933
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
1233 PM PDT TUE JUL 31 2012

CAC065-312045-
/O.CON.KSGX.FF.W.0008.000000T0000Z-120731T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-
1233 PM PDT TUE JUL 31 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 145 PM PDT FOR
CENTRAL RIVERSIDE COUNTY...

AT 1222 PM PDT...RADAR SHOWED A LARGE AREA OF HEAVY RAIN PRODUCING 
FLASH FLOODING OVER THE EASTERN SLOPES OF THE LITTLE SAN BERNARDINO 
MOUNTAINS AND THE EASTERN SECTIONS OF THE COACHELLA VALLEY. 

FLASH FLOODING AND MUD FLOWS ARE MOST LIKELY ON DILLON ROAD 
NORTHEAST OF INDIO. FLASH FLOODING IS ALSO LIKELY ALONG INTERSTATE 
10 EAST OF COACHELLA. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DEBRIS FLOWS...INCLUDING MUD AND ROCK SLIDES...ARE EXPECTED WITH THIS
STORM. MUD SLIDES AND ROCK SLIDES CAN POTENTIALLY TRAP AND KILL
PEOPLE CAUGHT IN THEIR PATH.

&&

LAT...LON 3385 11613 3383 11613 3374 11600 3374 11594
      3352 11595 3352 11609 3391 11626 3391 11618

$$

MOEDE
880 
WGUS76 KSGX 312011
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
111 PM PDT TUE JUL 31 2012

CAC065-312045-
/O.CON.KSGX.FF.W.0008.000000T0000Z-120731T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-
111 PM PDT TUE JUL 31 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 145 PM PDT FOR
CENTRAL RIVERSIDE COUNTY...

AT 100 PM PDT...MODERATE RAIN CONTINUED OVER THE SOUTHERN COACHELLA 
VALLEY NEAR MECCA AND THERMAL. THE HEAVIEST RAIN WILL MOVE SOUTH OF 
THE VALLEY THROUGH 130 PM.  

URBAN AND STREET FLOODING WAS REPORTED IN INDIO AND COACHELLA AT 
1245 PM. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

&&

LAT...LON 3385 11613 3383 11613 3374 11600 3374 11594
      3352 11595 3352 11609 3391 11626 3391 11618

$$

MOEDE
090 
WGUS76 KSGX 312036
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
136 PM PDT TUE JUL 31 2012

CAC065-312036-
/O.CAN.KSGX.FF.W.0008.000000T0000Z-120731T2045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-
136 PM PDT TUE JUL 31 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR THE COACHELLA 
VALLEY...

AT 125 PM...RADAR SHOWED THE HEAVIEST RAINS HAD MOVED SOUTH OF THE 
COACHELLA VALLEY. 

BETWEEN NOON AND 1 PM...HEAVY RAIN FELL ACROSS BOX CANYON ROAD EAST 
OF MECCA...AND ALSO ON INTERSTATE 10 EAST OF INDIO. WEATHER SPOTTERS 
ALSO REPORTED STREET FLOODING IN INDIO.
 

LAT...LON 3385 11613 3383 11613 3374 11600 3374 11594
      3352 11595 3352 11609 3391 11626 3391 11618

$$

MOEDE

The office that day

Everything else NWS San Diego, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 30, 7:45 PM PDTFlash Flood WatchSGXRiverside, San Bernardino, San Diego23 hr
Jul 31, 1:23 PM PDTFlash Flood WarningSGXSan Diego82 min
Jul 31, 2:26 PM PDTFlash Flood WarningSGXRiverside109 min

Nearby

Flash Flood Warnings in California, 2012Every flash flood warning in 2012

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.